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• What is the difference between Anycast and GeoDNS / GeoIP wrt HA?

  - by Riyad

  Based on the Wikipedia description of Anycast, it includes both the distribution of a domain-name-to-many-IP-mapping across many DNS servers as well as replying to clients with the most geographically close (or fastest) server. In the context of a globally distributed, highly available site like google.com (or any CDN service with many global edge locations) this sounds like the two key features one would need. DNS services like Amazon's Route53, EasyDNS and DNSMadeEasy all advertise themselves as Anycast-enabled networks. Therefore my assumption is that each of these DNS services transparently offer me those two killer features: multi-IP-to-domain mapping AND routing clients to the closest node. However, each of these services seem to separate out these two functionalities, referring to the 2nd one (routing clients to closest node) as "GeoDNS", "GeoIP" or "Global Traffic Director" and charge extra for the service. If a core tenant of an Anycast-capable system is to already do this, why is this functionality being earmarked as this extra feature? What is this "GeoDNS" feature doing that a standard Anycast DNS service won't do (according to the definition of Anycast from Wikipedia -- I understand what is being advertised, just not why it isn't implied already). I get extra-confused when a DNS service like Route53 that doesn't support this nebulous "GeoDNS" feature lists functionality like: Fast – Using a global anycast network of DNS servers around the world, Route 53 is designed to automatically route your users to the optimal location depending on network conditions. As a result, the service offers low query latency for your end users, as well as low update latency for your DNS record management needs. ... which sounds exactly like what GeoDNS is intended to do, but geographically directing clients is something they explicitly don't support it yet. Ultimately I am looking for the two following features from a DNS provider: Map multiple IP addresses to a single domain name (like google.com, amazon.com, etc. does) Utilize a DNS service that will respond to client requests for that domain with the IP address of the nearest server to the requestee. As mentioned, it seems like this is all part of an "Anycast" DNS service (all of which these services are), but the features and marketing I see from them suggest otherwise, making me think I need to learn a bit more about how DNS works before making a deployment choice. Thanks in advance for any clarifications.

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• Subversion vision and roadmap

  - by gbjbaanb

  Recently C Michael Pilato of the core subversion team posted a mail to the subversion dev mailing list suggesting a vision and roadmap for the future of Subversion. Naturally, he wanted as much feedback and response as possible which is why I'm posting this here - to elicit some suggestions and contributions from you, the administrators of Subversion. Any comments are welcome, and I shall feedback a synopsis with a link to this question to the dev mailing list. Similarly, I've created a post on StackOverflow to get feedback from the programmer/user side of things too. So, without further ado: Vision The first thing on his "vision statement" is: Subversion has no future as a DVCS tool. Let's just get that out there. At least two very successful such tools exist already, and to squeeze another horse into that race would be a poor investment of energy and talent. There's no need to suggest distributed features for subversion. If you want a DVCS, there should be no ill-feeling if you migrate to Git, Mercurial or Bazaar. As he says, its pointless trying to make SVN like them when they already exist, especially when there are different usage patterns that SVN should be targetting. The vision for Subversion is: Subversion exists to be universally recognized and adopted as an open-source, centralized version control system characterized by its reliability as a safe haven for valuable data; the simplicity of its model and usage; and its ability to support the needs of a wide variety of users and projects, from individuals to large-scale enterprise operations. Roadmap Several ideas were suggested as being "very nice to have" and are offered as the starting point of a future roadmap. These are: Obliterate Shelve/Checkpoint Repository-dictated Configuration Rename Tracking Improved Merging Improved Tree Conflict Handling Enterprise Authentication Mechanisms Forward History Searching Log Message Templates Repository-dictated Configuration If anyone has suggestions to add, or comments on these, the subversion community would welcome all of them. Community And lastly, there was a call for more people to become involved with Subversion development. As with most OSS projects it can be daunting to join, but there is now a push for more to be done to help. If you feel like you can contribute, please do so.

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• In search of a network file system with extended caching to speed up file access

  - by Brecht Machiels

  I'm running a small home server that stores my documents. The disks in this server are in a RAID 1 configuration (using Linux md) and it's also periodically being backup up to an external hard drive to make sure I don't lose them. However, I'm always accessing the files from other computers on the home network using an SMB share, and this results in a considerable speed penalty (especially when connected over WLAN). This is quite annoying when editing large files, such as digital camera RAWs, for example. I've been looking for a solution to this problem. It would have to offer some kind of local caching to speed up the file access. The client would preferably not keep a copy of all data on the server, as it consists of a very large collection of photographs, most of which I will not access frequently. Instead, it should only cache the accessed files and sync the changes back in the background. Ideally, it would also do some smart read-ahead (cache the files that are in the same directory as the currently opened file, for examples), but I suppose that's asking a bit much. Synchronization should be automatic (on file change). Conflicting file changes (at the same time on different clients) are unlikely to happen in my use case, but I would prefer if they are handled properly (notification to the user). I've come across the following options, so far: something similar to Dropbox. iFolder seems to be the only thing that comes close, but its reputation (stability) and requirements put me off. A distributed file system such as OpenAFS. I'm not sure this will speed up file access. It is probably overkill for what I need. Maybe NFS or even Samba offer these possibilities. I read a bit about Windows' Offline Files, but its operation seems limited (at least on Windows XP). As this is just for personal use, I'm not willing to spend a lot of money. A free solution would be preferred. Also, the server needs to run on Linux, and I need a client for at least Windows.

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• Link aggregation with freebsd8 and a cicso 3550, what am i doing wrong?

  - by Flamewires

  Hey, I am trying to setup Link Aggrigation with LACP (well, anything that provides increased bandwidth and failover using my setup will work). I'm running FreeBSD 8.0 on 3 machines. M1 is running 2 10/100 ethernetcards setup for link aggrigation using lagg. for reference: ifconfig em0 up ifconfig tx0 up ifconfig create lagg0 ifconfig lagg0 laggproto lacp laggport tx0 laggport em0 192.168.1.16 netmask 255.255.255.0 I plugged them into ports 1 and 2 of a Cicso 3550. then ran: configure terminal interface range Fa0/1 - 2 switchport mode access switchport access vlan 1 channel-group 1 mode active (everythings in vlan 1) Now Im able to connect the other computers to other ports on the switch and failover works great, i can unplug cables in the middle of a transfer and the traffic gets rerouted. However, im not noticing any speed increase. My test setup: load balancing: i tried dst and src on the switch, neither seemed to give me a speed increase. I am SCPing 2 500 meg files from the lagg computer to other computers (one each) which are also running 10/100 full duplex cards. I get transfer speeds of about 11.2-11.4 Mbps to a single host, and about half that (5.9-6.2) Mbps when transferring to both at the same time. From what I understood with destination load balancing the router was suppose to balance traffic headed for 1 computer over 1 port and traffic headed for another over a diff(in this case) the other port. With destination-MAC address forwarding, when packets are forwarded to an EtherChannel, the packets are distributed across the ports in the channel based on the destination host MAC address of the incoming packet. Therefore, packets to the same destination are forwarded over the same port, and packets to a different destination are sent on a different port in the channel. For the 3550 series switch, when source-MAC address forwarding is used, load distribution based on the source and destination IP address is also enabled for routed IP traffic. All routed IP traffic chooses a port based on the source and destination IP address. Packets between two IP hosts always use the same port in the channel, and traffic between any other pair of hosts can use a different port in the channel. (Link) What am i doing wrong/what would i need to do to see a speed increase beyond what i could do with just a single card?

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• Is Steam for Mac effectively running as superuser?

  - by godDLL

  When you download the client it does not weigh too much, and seems to do very little. Inside the app bundle there is a script that—upon inspecting the environment and deciding you're not running Linux—launches the client, which downloads the full support environment and resources. For this to happen (all of this is saved inside the bundle, the app bundle gets updated in this process) Steam wants Universal Access for Assistive Devices, and your password. Cacheable resources, preferences (like keyboard shortcuts), support files (like game hardware requirement lookup tables) live inside the bundle, not in ~/Library/{Application Support|Preferences|Cache}; games' data get dumped into ~/Documents/Steam Content. I'd describe myself as a bit OCD (which really says a lot), and I wouldn't care that much still. I'd go comb this hairy mess and find out where stuff is, when and if I need to, even if it's in an unfamiliar place; that does not actually tick me off. Well, a little bit. What makes me concerned is the way Steam needs both Access for Assistive Devices, and my password to run. The former gives it the ability to talk very intimately with running apps and the underlying system; while the latter (admin account) could very well give it and it's publishers unrestricted access to all my software, hardware and data. With publishers like Rockstar using scene NOCD cracks to publish their games on Steam, I'm not so sure I'm OK with this. I'd like more games made available for the MacOS X and all the pretty machines that run it, but this arrangement does not seem very Mac-like to me. It looks like Valve is going around system security measures and best practices, foregoing sandboxing, code signing, relatively sane structured organization; all the things that would appeal to someone who's no fun at parties at all, and will die alone, in his long dead mother's basement… wait. Right. Anyway. Can we get some input on Steam for Mac security at the end-user machine, from someone who understands how Accessibility API works, whether games distributed on Steam can read and write outside the user homefolder, collect data from other running apps, or similar?

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• Setting up a home server - what to use? (ZFS vs btrfs, BSD vs Linux, misc other requirements)

  - by monch1962

  I need to get all our home content off individual machines and onto a central server. What I'd like to have is the metaphorical "server under the stairs". Stuff we need: expandable storage. I want to be able to add extra disc as we go along, with minimal maintenance required. Currently we've got about 3Tb of files we need to host, and that's likely to grow by another Tb every 6-12 months based on recent history. I need to be able to add additional disc with minimal pain needs to store all the media (i.e. photos, video, music) we have, and run services to serve the various devices we have in the house to playback (e.g. DAAP so we can play stuff through iTunes, ccxstream so we can play stuff over XBMC). DAAP and ccxstream are needed now, but we also need to support new standards as they emerge (so a closed-box solution isn't going to work) RAID 5, or something broadly equivalent (e.g. RAID-Z) BitTorrent client ssh, NFS, Samba access snapshot capability (as in ZFS), so we can snapshot individual file systems regularly and rollback when my kids delete their school assignments the day before they're due... ability to recover quickly from power outages (it's not unusual for us to have power outages that last longer than our UPS' batteries) FOSS software a modern distributed version control system running on the box, such as Mercurial Stuff I'd like to have on the server, but can live without: PVR capability, so I could record TV to the box Web server. We currently run a small Web server on a very old box, and I'd ideally like to turn the old box off and move the content to the new server just to save some electricity Nagios + mrtg I've been looking at using a EEE Box as the server, primarily because I can get them cheap and they don't consume much power. The choice of OS and file system is more difficult, from what I've found: I've got most experience with various Linux distros, but am happy to use another Unix FreeBSD and OpenSolaris seem to be the best choices for hosting ZFS OpenSolaris' hardware support is nowhere near as good as e.g. Ubuntu btrfs, while looking very good, doesn't seem ready for prime-time yet ZFS doesn't let you (easily?) add new discs to a RAID5 or RAID-Z reading around, it seems that ZFS is a bit short of tools for recovering lost data At the moment, I'm leaning towards running FreeNAS+ZFS, but I'm concerned about the requirement to be able to add new disc on a fairly regular basis to an existing RAID-Z. Can anyone provide some recommendations, or share experiences? Thanks in advance

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• Setting up a home server - what to use? (ZFS vs btrfs, BSD vs Linux, misc other requirements)

  - by monch1962

  I need to get all our home content off individual machines and onto a central server. What I'd like to have is the metaphorical "server under the stairs". Stuff we need: expandable storage. I want to be able to add extra disc as we go along, with minimal maintenance required. Currently we've got about 3Tb of files we need to host, and that's likely to grow by another Tb every 6-12 months based on recent history. I need to be able to add additional disc with minimal pain needs to store all the media (i.e. photos, video, music) we have, and run services to serve the various devices we have in the house to playback (e.g. DAAP so we can play stuff through iTunes, ccxstream so we can play stuff over XBMC). DAAP and ccxstream are needed now, but we also need to support new standards as they emerge (so a closed-box solution isn't going to work) RAID 5, or something broadly equivalent (e.g. RAID-Z) BitTorrent client ssh, NFS, Samba access snapshot capability (as in ZFS), so we can snapshot individual file systems regularly and rollback when my kids delete their school assignments the day before they're due... ability to recover quickly from power outages (it's not unusual for us to have power outages that last longer than our UPS' batteries) FOSS software a modern distributed version control system running on the box, such as Mercurial Stuff I'd like to have on the server, but can live without: PVR capability, so I could record TV to the box Web server. We currently run a small Web server on a very old box, and I'd ideally like to turn the old box off and move the content to the new server just to save some electricity Nagios + mrtg I've been looking at using a EEE Box as the server, primarily because I can get them cheap and they don't consume much power. The choice of OS and file system is more difficult, from what I've found: I've got most experience with various Linux distros, but am happy to use another Unix FreeBSD and OpenSolaris seem to be the best choices for hosting ZFS OpenSolaris' hardware support is nowhere near as good as e.g. Ubuntu btrfs, while looking very good, doesn't seem ready for prime-time yet ZFS doesn't let you (easily?) add new discs to a RAID5 or RAID-Z reading around, it seems that ZFS is a bit short of tools for recovering lost data At the moment, I'm leaning towards running FreeNAS+ZFS, but I'm concerned about the requirement to be able to add new disc on a fairly regular basis to an existing RAID-Z. Can anyone provide some recommendations, or share experiences? Thanks in advance

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• Setting up a home server - what to use? (ZFS vs btrfs, BSD vs Linux, misc other requirements)

  - by monch1962

  I need to get all our home content off individual machines and onto a central server. What I'd like to have is the metaphorical "server under the stairs". Stuff we need: expandable storage. I want to be able to add extra disc as we go along, with minimal maintenance required. Currently we've got about 3Tb of files we need to host, and that's likely to grow by another Tb every 6-12 months based on recent history. I need to be able to add additional disc with minimal pain needs to store all the media (i.e. photos, video, music) we have, and run services to serve the various devices we have in the house to playback (e.g. DAAP so we can play stuff through iTunes, ccxstream so we can play stuff over XBMC). DAAP and ccxstream are needed now, but we also need to support new standards as they emerge (so a closed-box solution isn't going to work) RAID 5, or something broadly equivalent (e.g. RAID-Z) BitTorrent client ssh, NFS, Samba access snapshot capability (as in ZFS), so we can snapshot individual file systems regularly and rollback when my kids delete their school assignments the day before they're due... ability to recover quickly from power outages (it's not unusual for us to have power outages that last longer than our UPS' batteries) FOSS software a modern distributed version control system running on the box, such as Mercurial Stuff I'd like to have on the server, but can live without: PVR capability, so I could record TV to the box Web server. We currently run a small Web server on a very old box, and I'd ideally like to turn the old box off and move the content to the new server just to save some electricity Nagios + mrtg I've been looking at using a EEE Box as the server, primarily because I can get them cheap and they don't consume much power. The choice of OS and file system is more difficult, from what I've found: I've got most experience with various Linux distros, but am happy to use another Unix FreeBSD and OpenSolaris seem to be the best choices for hosting ZFS OpenSolaris' hardware support is nowhere near as good as e.g. Ubuntu btrfs, while looking very good, doesn't seem ready for prime-time yet ZFS doesn't let you (easily?) add new discs to a RAID5 or RAID-Z reading around, it seems that ZFS is a bit short of tools for recovering lost data At the moment, I'm leaning towards running FreeNAS+ZFS, but I'm concerned about the requirement to be able to add new disc on a fairly regular basis to an existing RAID-Z. Can anyone provide some recommendations, or share experiences? Thanks in advance

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• Linux filesystem with inodes close on the disk

  - by pts

  I'd like to make the ls -laR /media/myfs on Linux as fast as possible. I'll have 1 million files on the filesystem, 2TB of total file size, and some directories containing as much as 10000 files. Which filesystem should I use and how should I configure it? As far as I understand, the reason why ls -laR is slow because it has to stat(2) each inode (i.e. 1 million stat(2)s), and since inodes are distributed randomly on the disk, each stat(2) needs one disk seek. Here are some solutions I had in mind, none of which I am satisfied with: Create the filesystem on an SSD, because the seek operations on SSDs are fast. This wouldn't work, because a 2TB SSD doesn't exist, or it's prohibitively expensive. Create a filesystem which spans on two block devices: an SSD and a disk; the disk contains file data, and the SSD contains all the metadata (including directory entries, inodes and POSIX extended attributes). Is there a filesystem which supports this? Would it survive a system crash (power outage)? Use find /media/myfs on ext2, ext3 or ext4, instead of ls -laR /media/myfs, because the former can the advantage of the d_type field (see in the getdents(2) man page), so it doesn't have to stat. Unfortunately, this doesn't meet my requirements, because I need all file sizes as well, which find /media/myfs doesn't print. Use a filesystem, such as VFAT, which stores inodes in the directory entries. I'd love this one, but VFAT is not reliable and flexible enough for me, and I don't know of any other filesystem which does that. Do you? Of course, storing inodes in the directory entries wouldn't work for files with a link count more than 1, but that's not a problem since I have only a few dozen such files in my use case. Adjust some settings in /proc or sysctl so that inodes are locked to system memory forever. This would not speed up the first ls -laR /media/myfs, but it would make all subsequent invocations amazingly fast. How can I do this? I don't like this idea, because it doesn't speed up the first invocation, which currently takes 30 minutes. Also I'd like to lock the POSIX extended attributes in memory as well. What do I have to do for that? Use a filesystem which has an online defragmentation tool, which can be instructed to relocate inodes to the the beginning of the block device. Once the relocation is done, I can run dd if=/dev/sdb of=/dev/null bs=1M count=256 to get the beginning of the block device fetched to the kernel in-memory cache without seeking, and then the stat(2) operations would be fast, because they read from the cache. Is there a way to lock those inodes and/or blocks into memory once they have been read? Which filesystem has such a defragmentation tool?

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• Apache redirect multiple domain names from https

  - by Cyril N.

  My server distribute two main websites, says : www.google.com & www.facebook.com (yeah I know :p) I want them to be distributed via https. Using Apache, I defined a vhost file in sites-available/enabled containing this : <VirtualHost *:80> ServerName google.com Redirect / https://www.google.com/ </VirtualHost> <VirtualHost *:80> ServerName facebook.com Redirect / https://www.facebook.com/ </VirtualHost> <VirtualHost *:80> DocumentRoot /srv/www/google/www/ ServerName www.google.com ServerAlias www.facebook.com <Directory ... /> # Google & Facebook points to the same directory (crazy right ?) # Next of the config </VirtualHost> <VirtualHost *:443> SSLEngine On SSLCertificateFile /path/to/google.crt SSLCertificateKeyFile /path/to/google.key DocumentRoot "/srv/www/google/www/" ServerName www.google.com <Directory .../> # Next of the config </VirtualHost> <VirtualHost *:443> SSLEngine On SSLCertificateFile /path/to/facebook.crt SSLCertificateKeyFile /path/to/facebook.key DocumentRoot "/srv/www/google/www/" ServerName www.facebook.com <Directory .../> # Next of the config </VirtualHost> If I access to https://www.google.com, the httpS works correctly If I access to https://www.facebook.com, the httpS works correctly. If I access to http://www.google.com, the http works correctly # Without https ! If I access to http://www.facebook.com, the http works correctly # Without https ! BUT : If I access to https://facebook.com, it fails saying that the SSL connection is not what expected : Google.com instead of facebook.com Based on my configuration file, I understand why, so I tried to add : <VirtualHost *:443> SSLEngine On ServerName facebook.com Redirect / https://www.facebook.com/ </VirtualHost> But then, I can't even access facebook.com nor www.facebook.com via http/https. So my question is quite simple : how can I redirect all https access to facebook.com (and eventually all sub facebooks : facebook.fr, www.facebook.fr, etc) to www.facebook.com (redirecting to www domain) in HTTPS ? Thanks for your help ! :)

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• Why do I sometimes get 'sh: $'\302\211 ... ': command not found' in xterm/sh?

  - by amn

  Sometimes when I simply type a valid command like 'find ...', or anything really, I get back the following, which is completely unexpected and confusing (... is command name I type): sh: $'\302\211...': command not found There is some corruption going on I think. I don't use color in my prompt, I am using the Bash shell in POSIX mode as sh (chsh to /bin/sh and so on - $SHELL is sh). What is going on and why does this keep happening? Anything I can debug? I think this is more of an xterm issue than sh, or at least a combination of the two. Files, for context: My /etc/profile, as distributed with Arch Linux x86-64: # /etc/profile #Set our umask umask 022 # Set our default path PATH="/usr/local/sbin:/usr/local/bin:/usr/bin" export PATH # Load profiles from /etc/profile.d if test -d /etc/profile.d/; then for profile in /etc/profile.d/*.sh; do test -r "$profile" && . "$profile" done unset profile fi # Source global bash config if test "$PS1" && test "$BASH" && test -r /etc/bash.bashrc; then . /etc/bash.bashrc fi # Termcap is outdated, old, and crusty, kill it. unset TERMCAP # Man is much better than us at figuring this out unset MANPATH My /etc/shrc, which I created as a way to have sh parse some file on startup, when non-login shell. This is achieved using ENV variable set in /etc/environment with the line ENV=/etc/shrc: PS1='\u@\H \w \$ ' alias ls='ls -F --color' alias grep='grep -i --color' [ -f ~/.shrc ] && . ~/.shrc My ~/.profile, I am launching X when logging in through first virtual tty: [[ -z $DISPLAY && $XDG_VTNR -eq 1 ]] && exec xinit -- -dpi 111 My ~/.xinitc, as you can see I am using the system as a Virtual Box guest: xrdb -merge ~/.Xresources VBoxClient-all awesome & exec xterm And finally, my ~/.Xresources, no fancy stuff here I guess: *faceName: Inconsolata *faceSize: 10 xterm*VT100*translations: #override <Btn1Up>: select-end(PRIMARY, CLIPBOARD, CUT_BUFFER0) xterm*colorBDMode: true xterm*colorBD: #ff8000 xterm*cursorColor: S_red Since ~/.profile references among other things /etc/bash.bashrc, here is its content: # # /etc/bash.bashrc # # If not running interactively, don't do anything [[ $- != *i* ]] && return PS1='[\u@\h \W]\$ ' PS2='> ' PS3='> ' PS4='+ ' case ${TERM} in xterm*|rxvt*|Eterm|aterm|kterm|gnome*) PROMPT_COMMAND=${PROMPT_COMMAND:+$PROMPT_COMMAND; }'printf "\033]0;%s@%s:%s\007" "${USER}" "${HOSTNAME%%.*}" "${PWD/#$HOME/~}"' ;; screen) PROMPT_COMMAND=${PROMPT_COMMAND:+$PROMPT_COMMAND; }'printf "\033_%s@%s:%s\033\\" "${USER}" "${HOSTNAME%%.*}" "${PWD/#$HOME/~}"' ;; esac [ -r /usr/share/bash-completion/bash_completion ] && . /usr/share/bash-completion/bash_completion I have no idea what that case statement does, by the way, it does look a bit suspicious though, but then again, who am I to know.

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• Squid on windows loadbalancing only to one server

  - by Martin L.

  After thousands of googles and trying days i cant get the load balancer/failover in squid on windows to work. Iam using squid 2.7. My webservers are 2 single NIC lighttpd and one dual nic lighttpd. server1 in this example is running squid on port 80 and lighttpd on port 8080 (just to test) Requirements: All 3 webservers running lighttpd should be balanced two option for load balancing: Best would be if server1 is busy server2 takes over, if server2 is busy server3 takes over, etc.. Round robin style evenly distributed load. Eg server1 takes first call, server2 second etc.. All requests should be treated the same way (no url rewriting or so on) Sent host headers have to be redirected to every server as http host header, speaking of "server1", "server1.company.internal" and "10.211.1.1". My approach: acl all src all acl manager proto cache_object http_port 80 accel defaultsite=server1.company.internal vhost #reverse proxy entries cache_peer 10.211.2.1 parent 8080 0 no-query originserver round-robin login=PASS name=server1_nic1 cache_peer 10.211.1.2 parent 80 0 no-query originserver round-robin login=PASS name=server2_nic1 cache_peer 10.211.2.3 parent 8080 0 no-query originserver round-robin login=PASS name=server3_nic1 cache_peer 10.211.2.4 parent 8080 0 no-query originserver round-robin login=PASS name=server3_nic2 #decl of names of squid host acl registered_name_hostdomain dstdomain server1.company.internal acl registered_name_host dstdomain server1 #ip of squid host acl registered_name_ip dstdomain 10.211.2.1 # access: redirects the correct squid hostname http_access allow registered_name_hostdomain http_access allow registered_name_host http_access allow registered_name_ip http_access deny all cache_peer_access server1_nic1 allow registered_name_hostdomain cache_peer_access server1_nic1 allow registered_name_host cache_peer_access server1_nic1 allow registered_name_ip cache_peer_access server2_nic1 allow registered_name_hostdomain cache_peer_access server2_nic1 allow registered_name_host cache_peer_access server2_nic1 allow registered_name_ip cache_peer_access server3_nic1 allow registered_name_hostdomain cache_peer_access server3_nic1 allow registered_name_host cache_peer_access server3_nic1 allow registered_name_ip cache_peer_access server3_nic2 allow registered_name_hostdomain cache_peer_access server3_nic2 allow registered_name_host cache_peer_access server3_nic2 allow registered_name_ip cache_peer_access server1_nic1 deny all cache_peer_access server2_nic1 deny all cache_peer_access server3_nic1 deny all cache_peer_access server3_nic2 deny all never_direct allow all Problems: Load balancer does not load balance other than to first server. Only if the first server is killed in any way the second will take over. I have seen the others working at some point, but definitely not as the intended load balancing described above. If the cache_peer_access is not defined sometimes the wrong hostname is sent to the backend webserver and this always depends on the defaultsite= parameter. Probably because the host header on the request to squid is not set and its replaced by defaultsite. Leaving out defaultsite didnt solve the problem. The only workaround i found for this is the current approach with cache_peer_access. Questions: Does the cache_peer_access influence the round-robin? Is there a better workaround to pass the host header to the backed webservers? Which parameters do increase the speed of load balancing or does anyone have a better approach? -Martin

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• Create and manage child name servers (glue records) within my domain?

  - by basilmir

  Preface I use a top level domain provider that only allows me to add "normal" third-party name servers (a list where i can add "ns1.hostingcompany.com" type entries... nothing else) AND "child name servers" which i can later attach to my parent account ( ns1.myowndomain.com and an ip address). They do not provide other means of linking up. I want to host my own server and dns, even with just one name server (at first). My setup: Airport Extreme - get's a static ip address from my ISP Mac Mini Server - sits behind the Airport and get's a 10.0.1.2 My problem is that i can't seem to configure DNS correctly. I added a "child nameserver" with my airport's external static ip address at the top level provider, so to my understanding i should have all DNS traffic redirected to my Airport. I've opened port 53 UDP to let the traffic in. Now, what i don't get is this. My Mini Server is sitting on a 10.0.1.2 address and i have setup dns correctly, with an A record to point and resolve my server AND a reverse lookup to that 10.0.1.2. So it's ok for "internal stuff". Here is the clicker... How, when a request comes from the exterior for a reverse lookup, does the server "know" ... well look i have everything in 10.0.1.2 but the guy outside needs something from my real address. I can't begin to describe the MX record bonanza... How do i set this "right"? Do i "need" my Mini Server to sit on the external address directly (i can see how this could be the preferred solution, being close to a "real" server i have in my mind). If not... do i need a PTR record on the 10.0.1.2 server but with the external address in there? My dream: I will extend this "setup" with multiple Mini's in different cities where i work. I want a distributed something (Xgrid comes to mind). PS. Be gentle, i've read 2 books and the subject, and bought both the Lynda Essentials and DNS and Networking to boot, still i'm far from being on top of things.

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• Troubleshooting Network Speeds -- The Age Old Inquiry

  - by John K

  I'm looking for help with what I'm sure is an age old question. I've found myself in a situation of yearning to understand network throughput more clearly, but I can't seem to find information that makes it "click" We have a few servers distributed geographically, running various versions of Windows. Assuming we always use one host (a desktop) as the source, when copying data from that host to other servers across the country, we see a high variance in speed. In some cases, we can copy data at 12MB/s consistently, in others, we're seeing 0.8 MB/s. It should be noted, after testing 8 destinations, we always seem to be at either 0.6-0.8MB/s or 11-12 MB/s. In the building we're primarily concerned with, we have an OC-3 connection to our ISP. I know there are a lot of variables at play, but I guess I was hoping the experts here could help answer a few basic questions to help bolster my understanding. 1.) For older machines, running Windows XP, server 2003, etc, with a 100Mbps Ethernet card and 72 ms typical latency, does 0.8 MB/s sound at all reasonable? Or do you think that slow enough to indicate a problem? 2.) The classic "mathematical fastest speed" of "throughput = TCP window / latency," is, in our case, calculated to 0.8 MB/s (64Kb / 72 ms). My understanding is that is an upper bounds; that you would never expect to reach (due to overhead) let alone surpass that speed. In some cases though, we're seeing speeds of 12.3 MB/s. There are Steelhead accelerators scattered around the network, could those account for such a higher transfer rate? 3.) It's been suggested that the use SMB vs. SMB2 could explain the differences in speed. Indeed, as expected, packet captures show both being used depending on the OS versions in play, as we would expect. I understand what determines SMB2 being used or not, but I'm curious to know what kind of performance gain you can expect with SMB2. My problem simply seems to be a lack of experience, and more importantly, perspective, in terms of what are and are not reasonable network speeds. Could anyone help impart come context/perspective?

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• Is there a way to replicate a very large file shares in real-time?

  - by fsckin

  I have an hourly cron job that copies about 40GB of data from a source folder into a new folder with the hour appended on the end. When it's done, the job prunes anything older than 24 hours. This data changes very often during work hours and is on a samba file share. Here's how the folder structure looks: \server\Version.1 \server\Version.2 \server\Version.3 ... \server\Version.24 The contents of each new folder compared to the last one usually doesn't change very much, since this is a hourly job. Now you might be thinking that I'm an idiot for setting dreaming this up. Truth is, I just found out. It's actually been used for years and is so incredibly simple, anyone could delete the ENTIRE 40GB share (imagine that dialog spooling up... deleting thousands and thousands of files) and it would actually be faster to restore by moving the latest copy back to the source than it took to delete. Brilliant! Now to top this off, I need to efficiently replicate this 960GB of "mostly similar" data to a remote server over WAN link, with the replication happening as close to real-time as possible -- think hot spare, disaster recovery, etc. My first thought was rsync. Total failure. Rsync sees it sees a deletion of the folder that is 24 hours old and the addition of a new folder with 30GB of data to sync! I also looked at rdiff-backup and unison, they both appear to use similar algorithms and do not keep enough meta-data to do this intelligently. Best thing that I can find "out of the box" to do this is Windows Server "Distributed Filesystem Replication" which uses "Remote Differential Compression" -- After reading the background information on how this works, it actually looks like exactly what I need. Problem: Both servers are running Linux. D'oh! One approach to this I'm looking at is this, say it's 5AM and the cron job finishes: New Version.5 folder arrives at on local server SSH to remote server and copy Version.4 to Version.5 Run rsync on the local server pushing changes to the remote server. Rsync finally knows to do a differential copy between Version.4 and Version.5 Is there a smarter way to replicate Samba shares as close to real-time as possible? Anything out there that does "Remote Differential Compression" on Linux?

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• 2 servers, high availability and faster response

  - by user17886

  I recently bought a second webserver because I worry about hardware failure of my old server. Now that I have that second server I wish to do a little more then just have one server standby and replicate all day. As long as it's there I might as well get some advantage our of it ! I have a website powered by ubuntu 12.04, nginx, php-fpm, apc, mysql (5.5) and couchdb. Im currently testing configurations where i can achieve failover AND make good use of the extra harware for faster responses / distributed load. The setup I am testing nowinvolves heartbeat for ip failover and two identical servers. Of the two servers only one has a public ip adress. If one server crashes the other server takes over the public ip adress. On an incoming request nginx forwards the request tot php-fpm to either server a of server b (50/50 if both servers are alive). Once the request has been send to php-fpm both servers look at localhost for the mysql server. I use master-master mysql replication for this. The file system is synced with lsyncd. This works pretty well but Im reading it's discouraged by the (mysql) community. Another option I could think of is to use one server as a mysql master and one server as a web/php server. The servers would still sync their filesystem, would still run the same duplicate software (nginx,mysql) but master slave mysql replication could be used. As long as bother servers are alive I could just prefer nginx to listen to ip a and mysql to ip b. If one server is down, the other server could take over the task of the other server, simply by ip switching. But im completely new at this so I would greatly value your expert advice. Is either of the two setups any good ? If you have any thoughts on this please let me know ! PS, virtualisation, hosting on different locations or active/passive setups are not solutions im looking for. I find virtual server either too slow or too expensive. I already have a passive failover on another location. But in case of a crash I found the site was still unreachable for too long due to dns caching.

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• Unable to install Xdebug

  - by burnt1ce

  I've registered xdebug in php.ini (as per http://xdebug.org/docs/install) but it's not showing up when i run "php -m" or when i get a test page to run "phpinfo()". I've just installed the latest version of XAMPP. Can anyone provide any suggestions in getting xdebug to show up? This is what i get when i run phpinfo(). **PHP Version 5.3.1** System Windows NT ANDREW_LAPTOP 5.1 build 2600 (Windows XP Professional Service Pack 3) i586 Build Date Nov 20 2009 17:20:57 Compiler MSVC6 (Visual C++ 6.0) Architecture x86 Configure Command cscript /nologo configure.js "--enable-snapshot-build" Server API Apache 2.0 Handler Virtual Directory Support enabled Configuration File (php.ini) Path no value Loaded Configuration File C:\xampp\php\php.ini Scan this dir for additional .ini files (none) Additional .ini files parsed (none) PHP API 20090626 PHP Extension 20090626 Zend Extension 220090626 Zend Extension Build API220090626,TS,VC6 PHP Extension Build API20090626,TS,VC6 Debug Build no Thread Safety enabled Zend Memory Manager enabled Zend Multibyte Support disabled IPv6 Support enabled Registered PHP Streams https, ftps, php, file, glob, data, http, ftp, compress.zlib, compress.bzip2, phar, zip Registered Stream Socket Transports tcp, udp, ssl, sslv3, sslv2, tls Registered Stream Filters convert.iconv.*, string.rot13, string.toupper, string.tolower, string.strip_tags, convert.*, consumed, dechunk, zlib.*, bzip2.* This program makes use of the Zend Scripting Language Engine: Zend Engine v2.3.0, Copyright (c) 1998-2009 Zend Technologies PHP Credits Configuration apache2handler Apache Version Apache/2.2.14 (Win32) DAV/2 mod_ssl/2.2.14 OpenSSL/0.9.8l mod_autoindex_color PHP/5.3.1 mod_apreq2-20090110/2.7.1 mod_perl/2.0.4 Perl/v5.10.1 Apache API Version 20051115 Server Administrator postmaster@localhost Hostname:Port localhost:80 Max Requests Per Child: 0 - Keep Alive: on - Max Per Connection: 100 Timeouts Connection: 300 - Keep-Alive: 5 Virtual Server No Server Root C:/xampp/apache Loaded Modules core mod_win32 mpm_winnt http_core mod_so mod_actions mod_alias mod_asis mod_auth_basic mod_auth_digest mod_authn_default mod_authn_file mod_authz_default mod_authz_groupfile mod_authz_host mod_authz_user mod_cgi mod_dav mod_dav_fs mod_dav_lock mod_dir mod_env mod_headers mod_include mod_info mod_isapi mod_log_config mod_mime mod_negotiation mod_rewrite mod_setenvif mod_ssl mod_status mod_autoindex_color mod_php5 mod_perl mod_apreq2 Directive Local Value Master Value engine 1 1 last_modified 0 0 xbithack 0 0 Apache Environment Variable Value MIBDIRS C:/xampp/php/extras/mibs MYSQL_HOME C:\xampp\mysql\bin OPENSSL_CONF C:/xampp/apache/bin/openssl.cnf PHP_PEAR_SYSCONF_DIR C:\xampp\php PHPRC C:\xampp\php TMP C:\xampp\tmp HTTP_HOST localhost HTTP_CONNECTION keep-alive HTTP_USER_AGENT Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US) AppleWebKit/533.2 (KHTML, like Gecko) Chrome/5.0.342.8 Safari/533.2 HTTP_CACHE_CONTROL max-age=0 HTTP_ACCEPT application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5 HTTP_ACCEPT_ENCODING gzip,deflate,sdch HTTP_ACCEPT_LANGUAGE en-US,en;q=0.8 HTTP_ACCEPT_CHARSET ISO-8859-1,utf-8;q=0.7,*;q=0.3 PATH C:\Documents and Settings\Andrew\Local Settings\Application Data\Google\Chrome\Application;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;c:\Program Files\Microsoft SQL Server\100\Tools\Binn\;c:\Program Files\Microsoft SQL Server\100\DTS\Binn\;C:\Program Files\QuickTime\QTSystem\;C:\Program Files\Common Files\DivX Shared\;C:\Program Files\WiTopia.Net\bin SystemRoot C:\WINDOWS COMSPEC C:\WINDOWS\system32\cmd.exe PATHEXT .COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH WINDIR C:\WINDOWS SERVER_SIGNATURE <address>Apache/2.2.14 (Win32) DAV/2 mod_ssl/2.2.14 OpenSSL/0.9.8l mod_autoindex_color PHP/5.3.1 mod_apreq2-20090110/2.7.1 mod_perl/2.0.4 Perl/v5.10.1 Server at localhost Port 80</address> SERVER_SOFTWARE Apache/2.2.14 (Win32) DAV/2 mod_ssl/2.2.14 OpenSSL/0.9.8l mod_autoindex_color PHP/5.3.1 mod_apreq2-20090110/2.7.1 mod_perl/2.0.4 Perl/v5.10.1 SERVER_NAME localhost SERVER_ADDR 127.0.0.1 SERVER_PORT 80 REMOTE_ADDR 127.0.0.1 DOCUMENT_ROOT C:/xampp/htdocs SERVER_ADMIN postmaster@localhost SCRIPT_FILENAME C:/xampp/htdocs/test.php REMOTE_PORT 3275 GATEWAY_INTERFACE CGI/1.1 SERVER_PROTOCOL HTTP/1.1 REQUEST_METHOD GET QUERY_STRING no value REQUEST_URI /test.php SCRIPT_NAME /test.php HTTP Headers Information HTTP Request Headers HTTP Request GET /test.php HTTP/1.1 Host localhost Connection keep-alive User-Agent Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US) AppleWebKit/533.2 (KHTML, like Gecko) Chrome/5.0.342.8 Safari/533.2 Cache-Control max-age=0 Accept application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5 Accept-Encoding gzip,deflate,sdch Accept-Language en-US,en;q=0.8 Accept-Charset ISO-8859-1,utf-8;q=0.7,*;q=0.3 HTTP Response Headers X-Powered-By PHP/5.3.1 Keep-Alive timeout=5, max=80 Connection Keep-Alive Transfer-Encoding chunked Content-Type text/html bcmath BCMath support enabled Directive Local Value Master Value bcmath.scale 0 0 bz2 BZip2 Support Enabled Stream Wrapper support compress.bz2:// Stream Filter support bzip2.decompress, bzip2.compress BZip2 Version 1.0.5, 10-Dec-2007 calendar Calendar support enabled com_dotnet COM support enabled DCOM support disabled .Net support enabled Directive Local Value Master Value com.allow_dcom 0 0 com.autoregister_casesensitive 1 1 com.autoregister_typelib 0 0 com.autoregister_verbose 0 0 com.code_page no value no value com.typelib_file no value no value Core PHP Version 5.3.1 Directive Local Value Master Value allow_call_time_pass_reference On On allow_url_fopen On On allow_url_include Off Off always_populate_raw_post_data Off Off arg_separator.input & & arg_separator.output &amp; &amp; asp_tags Off Off auto_append_file no value no value auto_globals_jit On On auto_prepend_file no value no value browscap C:\xampp\php\extras\browscap.ini C:\xampp\php\extras\browscap.ini default_charset no value no value default_mimetype text/html text/html define_syslog_variables Off Off disable_classes no value no value disable_functions no value no value display_errors On On display_startup_errors On On doc_root no value no value docref_ext no value no value docref_root no value no value enable_dl On On error_append_string no value no value error_log no value no value error_prepend_string no value no value error_reporting 22519 22519 exit_on_timeout Off Off expose_php On On extension_dir C:\xampp\php\ext C:\xampp\php\ext file_uploads On On highlight.bg #FFFFFF #FFFFFF highlight.comment #FF8000 #FF8000 highlight.default #0000BB #0000BB highlight.html #000000 #000000 highlight.keyword #007700 #007700 highlight.string #DD0000 #DD0000 html_errors On On ignore_repeated_errors Off Off ignore_repeated_source Off Off ignore_user_abort Off Off implicit_flush Off Off include_path .;C:\xampp\php\PEAR .;C:\xampp\php\PEAR log_errors Off Off log_errors_max_len 1024 1024 magic_quotes_gpc Off Off magic_quotes_runtime Off Off magic_quotes_sybase Off Off mail.add_x_header Off Off mail.force_extra_parameters no value no value mail.log no value no value max_execution_time 60 60 max_file_uploads 20 20 max_input_nesting_level 64 64 max_input_time 60 60 memory_limit 128M 128M open_basedir no value no value output_buffering no value no value output_handler no value no value post_max_size 128M 128M precision 14 14 realpath_cache_size 16K 16K realpath_cache_ttl 120 120 register_argc_argv On On register_globals Off Off register_long_arrays Off Off report_memleaks On On report_zend_debug On On request_order no value no value safe_mode Off Off safe_mode_exec_dir no value no value safe_mode_gid Off Off safe_mode_include_dir no value no value sendmail_from no value no value sendmail_path no value no value serialize_precision 100 100 short_open_tag Off Off SMTP localhost localhost smtp_port 25 25 sql.safe_mode Off Off track_errors Off Off unserialize_callback_func no value no value upload_max_filesize 128M 128M upload_tmp_dir C:\xampp\tmp C:\xampp\tmp user_dir no value no value user_ini.cache_ttl 300 300 user_ini.filename .user.ini .user.ini variables_order GPCS GPCS xmlrpc_error_number 0 0 xmlrpc_errors Off Off y2k_compliance On On zend.enable_gc On On ctype ctype functions enabled date date/time support enabled "Olson" Timezone Database Version 2009.18 Timezone Database internal Default timezone America/New_York Directive Local Value Master Value date.default_latitude 31.7667 31.7667 date.default_longitude 35.2333 35.2333 date.sunrise_zenith 90.583333 90.583333 date.sunset_zenith 90.583333 90.583333 date.timezone America/New_York America/New_York dom DOM/XML enabled DOM/XML API Version 20031129 libxml Version 2.7.6 HTML Support enabled XPath Support enabled XPointer Support enabled Schema Support enabled RelaxNG Support enabled ereg Regex Library System library enabled exif EXIF Support enabled EXIF Version 1.4 $Id: exif.c 287372 2009-08-16 14:32:32Z iliaa $ Supported EXIF Version 0220 Supported filetypes JPEG,TIFF Directive Local Value Master Value exif.decode_jis_intel JIS JIS exif.decode_jis_motorola JIS JIS exif.decode_unicode_intel UCS-2LE UCS-2LE exif.decode_unicode_motorola UCS-2BE UCS-2BE exif.encode_jis no value no value exif.encode_unicode ISO-8859-15 ISO-8859-15 fileinfo fileinfo support enabled version 1.0.5-dev filter Input Validation and Filtering enabled Revision $Revision: 289434 $ Directive Local Value Master Value filter.default unsafe_raw unsafe_raw filter.default_flags no value no value ftp FTP support enabled gd GD Support enabled GD Version bundled (2.0.34 compatible) FreeType Support enabled FreeType Linkage with freetype FreeType Version 2.3.11 T1Lib Support enabled GIF Read Support enabled GIF Create Support enabled JPEG Support enabled libJPEG Version 7 PNG Support enabled libPNG Version 1.2.40 WBMP Support enabled XBM Support enabled JIS-mapped Japanese Font Support enabled Directive Local Value Master Value gd.jpeg_ignore_warning 0 0 gettext GetText Support enabled hash hash support enabled Hashing Engines md2 md4 md5 sha1 sha224 sha256 sha384 sha512 ripemd128 ripemd160 ripemd256 ripemd320 whirlpool tiger128,3 tiger160,3 tiger192,3 tiger128,4 tiger160,4 tiger192,4 snefru snefru256 gost adler32 crc32 crc32b salsa10 salsa20 haval128,3 haval160,3 haval192,3 haval224,3 haval256,3 haval128,4 haval160,4 haval192,4 haval224,4 haval256,4 haval128,5 haval160,5 haval192,5 haval224,5 haval256,5 iconv iconv support enabled iconv implementation "libiconv" iconv library version 1.13 Directive Local Value Master Value iconv.input_encoding ISO-8859-1 ISO-8859-1 iconv.internal_encoding ISO-8859-1 ISO-8859-1 iconv.output_encoding ISO-8859-1 ISO-8859-1 imap IMAP c-Client Version 2007e SSL Support enabled json json support enabled json version 1.2.1 libxml libXML support active libXML Compiled Version 2.7.6 libXML Loaded Version 20706 libXML streams enabled mbstring Multibyte Support enabled Multibyte string engine libmbfl HTTP input encoding translation disabled mbstring extension makes use of "streamable kanji code filter and converter", which is distributed under the GNU Lesser General Public License version 2.1. Multibyte (japanese) regex support enabled Multibyte regex (oniguruma) version 4.7.1 Directive Local Value Master Value mbstring.detect_order no value no value mbstring.encoding_translation Off Off mbstring.func_overload 0 0 mbstring.http_input pass pass mbstring.http_output pass pass mbstring.http_output_conv_mimetypes ^(text/|application/xhtml\+xml) ^(text/|application/xhtml\+xml) mbstring.internal_encoding no value no value mbstring.language neutral neutral mbstring.strict_detection Off Off mbstring.substitute_character no value no value mcrypt mcrypt support enabled Version 2.5.8 Api No 20021217 Supported ciphers cast-128 gost rijndael-128 twofish arcfour cast-256 loki97 rijndael-192 saferplus wake blowfish-compat des rijndael-256 serpent xtea blowfish enigma rc2 tripledes Supported modes cbc cfb ctr ecb ncfb nofb ofb stream Directive Local Value Master Value mcrypt.algorithms_dir no value no value mcrypt.modes_dir no value no value mhash MHASH support Enabled MHASH API Version Emulated Support ming Ming SWF output library enabled Version 0.4.3 mysql MySQL Support enabled Active Persistent Links 0 Active Links 0 Client API version 5.1.41 Directive Local Value Master Value mysql.allow_local_infile On On mysql.allow_persistent On On mysql.connect_timeout 60 60 mysql.default_host no value no value mysql.default_password no value no value mysql.default_port 3306 3306 mysql.default_socket MySQL MySQL mysql.default_user no value no value mysql.max_links Unlimited Unlimited mysql.max_persistent Unlimited Unlimited mysql.trace_mode Off Off mysqli MysqlI Support enabled Client API library version 5.1.41 Active Persistent Links 0 Inactive Persistent Links 0 Active Links 0 Client API header version 5.1.41 MYSQLI_SOCKET MySQL Directive Local Value Master Value mysqli.allow_local_infile On On mysqli.allow_persistent On On mysqli.default_host no value no value mysqli.default_port 3306 3306 mysqli.default_pw no value no value mysqli.default_socket MySQL MySQL mysqli.default_user no value no value mysqli.max_links Unlimited Unlimited mysqli.max_persistent Unlimited Unlimited mysqli.reconnect Off Off mysqlnd mysqlnd enabled Version mysqlnd 5.0.5-dev - 081106 - $Revision: 289630 $ Command buffer size 4096 Read buffer size 32768 Read timeout 31536000 Collecting statistics Yes Collecting memory statistics No Client statistics bytes_sent 0 bytes_received 0 packets_sent 0 packets_received 0 protocol_overhead_in 0 protocol_overhead_out 0 bytes_received_ok_packet 0 bytes_received_eof_packet 0 bytes_received_rset_header_packet 0 bytes_received_rset_field_meta_packet 0 bytes_received_rset_row_packet 0 bytes_received_prepare_response_packet 0 bytes_received_change_user_packet 0 packets_sent_command 0 packets_received_ok 0 packets_received_eof 0 packets_received_rset_header 0 packets_received_rset_field_meta 0 packets_received_rset_row 0 packets_received_prepare_response 0 packets_received_change_user 0 result_set_queries 0 non_result_set_queries 0 no_index_used 0 bad_index_used 0 slow_queries 0 buffered_sets 0 unbuffered_sets 0 ps_buffered_sets 0 ps_unbuffered_sets 0 flushed_normal_sets 0 flushed_ps_sets 0 ps_prepared_never_executed 0 ps_prepared_once_executed 0 rows_fetched_from_server_normal 0 rows_fetched_from_server_ps 0 rows_buffered_from_client_normal 0 rows_buffered_from_client_ps 0 rows_fetched_from_client_normal_buffered 0 rows_fetched_from_client_normal_unbuffered 0 rows_fetched_from_client_ps_buffered 0 rows_fetched_from_client_ps_unbuffered 0 rows_fetched_from_client_ps_cursor 0 rows_skipped_normal 0 rows_skipped_ps 0 copy_on_write_saved 0 copy_on_write_performed 0 command_buffer_too_small 0 connect_success 0 connect_failure 0 connection_reused 0 reconnect 0 pconnect_success 0 active_connections 0 active_persistent_connections 0 explicit_close 0 implicit_close 0 disconnect_close 0 in_middle_of_command_close 0 explicit_free_result 0 implicit_free_result 0 explicit_stmt_close 0 implicit_stmt_close 0 mem_emalloc_count 0 mem_emalloc_ammount 0 mem_ecalloc_count 0 mem_ecalloc_ammount 0 mem_erealloc_count 0 mem_erealloc_ammount 0 mem_efree_count 0 mem_malloc_count 0 mem_malloc_ammount 0 mem_calloc_count 0 mem_calloc_ammount 0 mem_realloc_count 0 mem_realloc_ammount 0 mem_free_count 0 proto_text_fetched_null 0 proto_text_fetched_bit 0 proto_text_fetched_tinyint 0 proto_text_fetched_short 0 proto_text_fetched_int24 0 proto_text_fetched_int 0 proto_text_fetched_bigint 0 proto_text_fetched_decimal 0 proto_text_fetched_float 0 proto_text_fetched_double 0 proto_text_fetched_date 0 proto_text_fetched_year 0 proto_text_fetched_time 0 proto_text_fetched_datetime 0 proto_text_fetched_timestamp 0 proto_text_fetched_string 0 proto_text_fetched_blob 0 proto_text_fetched_enum 0 proto_text_fetched_set 0 proto_text_fetched_geometry 0 proto_text_fetched_other 0 proto_binary_fetched_null 0 proto_binary_fetched_bit 0 proto_binary_fetched_tinyint 0 proto_binary_fetched_short 0 proto_binary_fetched_int24 0 proto_binary_fetched_int 0 proto_binary_fetched_bigint 0 proto_binary_fetched_decimal 0 proto_binary_fetched_float 0 proto_binary_fetched_double 0 proto_binary_fetched_date 0 proto_binary_fetched_year 0 proto_binary_fetched_time 0 proto_binary_fetched_datetime 0 proto_binary_fetched_timestamp 0 proto_binary_fetched_string 0 proto_binary_fetched_blob 0 proto_binary_fetched_enum 0 proto_binary_fetched_set 0 proto_binary_fetched_geometry 0 proto_binary_fetched_other 0 init_command_executed_count 0 init_command_failed_count 0 odbc ODBC Support enabled Active Persistent Links 0 Active Links 0 ODBC library Win32 Directive Local Value Master Value odbc.allow_persistent On On odbc.check_persistent On On odbc.default_cursortype Static cursor Static cursor odbc.default_db no value no value odbc.default_pw no value no value odbc.default_user no value no value odbc.defaultbinmode return as is return as is odbc.defaultlrl return up to 4096 bytes return up to 4096 bytes odbc.max_links Unlimited Unlimited odbc.max_persistent Unlimited Unlimited openssl OpenSSL support enabled OpenSSL Library Version OpenSSL 0.9.8l 5 Nov 2009 OpenSSL Header Version OpenSSL 0.9.8l 5 Nov 2009 pcre PCRE (Perl Compatible Regular Expressions) Support enabled PCRE Library Version 8.00 2009-10-19 Directive Local Value Master Value pcre.backtrack_limit 100000 100000 pcre.recursion_limit 100000 100000 pdf PDF Support enabled PDFlib GmbH Version 7.0.4p4 PECL Version 2.1.6 Revision $Revision: 277110 $ PDO PDO support enabled PDO drivers mysql, odbc, sqlite, sqlite2 pdo_mysql PDO Driver for MySQL enabled Client API version 5.1.41 PDO_ODBC PDO Driver for ODBC (Win32) enabled ODBC Connection Pooling Enabled, strict matching pdo_sqlite PDO Driver for SQLite 3.x enabled SQLite Library 3.6.20 Phar Phar: PHP Archive support enabled Phar EXT version 2.0.1 Phar API version 1.1.1 CVS revision $Revision: 286338 $ Phar-based phar archives enabled Tar-based phar archives enabled ZIP-based phar archives enabled gzip compression enabled bzip2 compression enabled Native OpenSSL support enabled Phar based on pear/PHP_Archive, original concept by Davey Shafik. Phar fully realized by Gregory Beaver and Marcus Boerger. Portions of tar implementation Copyright (c) 2003-2009 Tim Kientzle. Directive Local Value Master Value phar.cache_list no value no value phar.readonly On On phar.require_hash On On Reflection Reflection enabled Version $Revision: 287991 $ session Session Support enabled Registered save handlers files user sqlite Registered serializer handlers php php_binary wddx Directive Local Value Master Value session.auto_start Off Off session.bug_compat_42 On On session.bug_compat_warn On On session.cache_expire 180 180 session.cache_limiter nocache nocache session.cookie_domain no value no value session.cookie_httponly Off Off session.cookie_lifetime 0 0 session.cookie_path / / session.cookie_secure Off Off session.entropy_file no value no value session.entropy_length 0 0 session.gc_divisor 100 100 session.gc_maxlifetime 1440 1440 session.gc_probability 1 1 session.hash_bits_per_character 5 5 session.hash_function 0 0 session.name PHPSESSID PHPSESSID session.referer_check no value no value session.save_handler files files session.save_path C:\xampp\tmp C:\xampp\tmp session.serialize_handler php php session.use_cookies On On session.use_only_cookies Off Off session.use_trans_sid 0 0 SimpleXML Simplexml support enabled Revision $Revision: 281953 $ Schema support enabled soap Soap Client enabled Soap Server enabled Directive Local Value Master Value soap.wsdl_cache 1 1 soap.wsdl_cache_dir /tmp /tmp soap.wsdl_cache_enabled 1 1 soap.wsdl_cache_limit 5 5 soap.wsdl_cache_ttl 86400 86400 sockets Sockets Support enabled SPL SPL support enabled Interfaces Countable, OuterIterator, RecursiveIterator, SeekableIterator, SplObserver, SplSubject Classes AppendIterator, ArrayIterator, ArrayObject, BadFunctionCallException, BadMethodCallException, CachingIterator, DirectoryIterator, DomainException, EmptyIterator, FilesystemIterator, FilterIterator, GlobIterator, InfiniteIterator, InvalidArgumentException, IteratorIterator, LengthException, LimitIterator, LogicException, MultipleIterator, NoRewindIterator, OutOfBoundsException, OutOfRangeException, OverflowException, ParentIterator, RangeException, RecursiveArrayIterator, RecursiveCachingIterator, RecursiveDirectoryIterator, RecursiveFilterIterator, RecursiveIteratorIterator, RecursiveRegexIterator, RecursiveTreeIterator, RegexIterator, RuntimeException, SplDoublyLinkedList, SplFileInfo, SplFileObject, SplFixedArray, SplHeap, SplMinHeap, SplMaxHeap, SplObjectStorage, SplPriorityQueue, SplQueue, SplStack, SplTempFileObject, UnderflowException, UnexpectedValueException SQLite SQLite support enabled PECL Module version 2.0-dev $Id: sqlite.c 289598 2009-10-12 22:37:52Z pajoye $ SQLite Library 2.8.17 SQLite Encoding iso8859 Directive Local Value Master Value sqlite.assoc_case 0 0 sqlite3 SQLite3 support enabled SQLite3 module version 0.7-dev SQLite Library 3.6.20 Directive Local Value Master Value sqlite3.extension_dir no value no value standard Dynamic Library Support enabled Internal Sendmail Support for Windows enabled Directive Local Value Master Value assert.active 1 1 assert.bail 0 0 assert.callback no value no value assert.quiet_eval 0 0 assert.warning 1 1 auto_detect_line_endings 0 0 default_socket_timeout 60 60 safe_mode_allowed_env_vars PHP_ PHP_ safe_mode_protected_env_vars LD_LIBRARY_PATH LD_LIBRARY_PATH url_rewriter.tags a=href,area=href,frame=src,input=src,form=,fieldset= a=href,area=href,frame=src,input=src,form=,fieldset= user_agent no value no value tokenizer Tokenizer Support enabled wddx WDDX Support enabled WDDX Session Serializer enabled xml XML Support active XML Namespace Support active libxml2 Version 2.7.6 xmlreader XMLReader enabled xmlrpc core library version xmlrpc-epi v. 0.54 php extension version 0.51 author Dan Libby homepage http://xmlrpc-epi.sourceforge.net open sourced by Epinions.com xmlwriter XMLWriter enabled xsl XSL enabled libxslt Version 1.1.26 libxslt compiled against libxml Version 2.7.6 EXSLT enabled libexslt Version 1.1.26 zip Zip enabled Extension Version $Id: php_zip.c 276389 2009-02-24 23:55:14Z iliaa $ Zip version 1.9.1 Libzip version 0.9.0 zlib ZLib Support enabled Stream Wrapper support compress.zlib:// Stream Filter support zlib.inflate, zlib.deflate Compiled Version 1.2.3 Linked Version 1.2.3 Directive Local Value Master Value zlib.output_compression Off Off zlib.output_compression_level -1 -1 zlib.output_handler no value no value Additional Modules Module Name Environment Variable Value no value ::=::\ no value C:=C:\xampp ALLUSERSPROFILE C:\Documents and Settings\All Users APPDATA C:\Documents and Settings\Andrew\Application Data CHROME_RESTART Google Chrome|Whoa! Google Chrome has crashed. Restart now?|LEFT_TO_RIGHT CHROME_VERSION 5.0.342.8 CLASSPATH .;C:\Program Files\QuickTime\QTSystem\QTJava.zip CommonProgramFiles C:\Program Files\Common Files COMPUTERNAME ANDREW_LAPTOP ComSpec C:\WINDOWS\system32\cmd.exe FP_NO_HOST_CHECK NO HOMEDRIVE C: HOMEPATH \Documents and Settings\Andrew LOGONSERVER \\ANDREW_LAPTOP NUMBER_OF_PROCESSORS 2 OS Windows_NT PATH C:\Documents and Settings\Andrew\Local Settings\Application Data\Google\Chrome\Application;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;c:\Program Files\Microsoft SQL Server\100\Tools\Binn\;c:\Program Files\Microsoft SQL Server\100\DTS\Binn\;C:\Program Files\QuickTime\QTSystem\;C:\Program Files\Common Files\DivX Shared\;C:\Program Files\WiTopia.Net\bin PATHEXT .COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH PROCESSOR_ARCHITECTURE x86 PROCESSOR_IDENTIFIER x86 Family 6 Model 15 Stepping 10, GenuineIntel PROCESSOR_LEVEL 6 PROCESSOR_REVISION 0f0a ProgramFiles C:\Program Files PROMPT $P$G QTJAVA C:\Program Files\QuickTime\QTSystem\QTJava.zip SESSIONNAME Console sfxcmd "C:\Documents and Settings\Andrew\My Documents\Downloads\xampp-win32-1.7.3.exe" sfxname C:\Documents and Settings\Andrew\My Documents\Downloads\xampp-win32-1.7.3.exe SystemDrive C: SystemRoot C:\WINDOWS TEMP C:\DOCUME~1\Andrew\LOCALS~1\Temp TMP C:\DOCUME~1\Andrew\LOCALS~1\Temp USERDOMAIN ANDREW_LAPTOP USERNAME Andrew USERPROFILE C:\Documents and Settings\Andrew VS100COMNTOOLS C:\Program Files\Microsoft Visual Studio 10.0\Common7\Tools\ windir C:\WINDOWS AP_PARENT_PID 2216 PHP Variables Variable Value _SERVER["MIBDIRS"] C:/xampp/php/extras/mibs _SERVER["MYSQL_HOME"] C:\xampp\mysql\bin _SERVER["OPENSSL_CONF"] C:/xampp/apache/bin/openssl.cnf _SERVER["PHP_PEAR_SYSCONF_DIR"] C:\xampp\php _SERVER["PHPRC"] C:\xampp\php _SERVER["TMP"] C:\xampp\tmp _SERVER["HTTP_HOST"] localhost _SERVER["HTTP_CONNECTION"] keep-alive _SERVER["HTTP_USER_AGENT"] Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US) AppleWebKit/533.2 (KHTML, like Gecko) Chrome/5.0.342.8 Safari/533.2 _SERVER["HTTP_CACHE_CONTROL"] max-age=0 _SERVER["HTTP_ACCEPT"] application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5 _SERVER["HTTP_ACCEPT_ENCODING"] gzip,deflate,sdch _SERVER["HTTP_ACCEPT_LANGUAGE"] en-US,en;q=0.8 _SERVER["HTTP_ACCEPT_CHARSET"] ISO-8859-1,utf-8;q=0.7,*;q=0.3 _SERVER["PATH"] C:\Documents and Settings\Andrew\Local Settings\Application Data\Google\Chrome\Application;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;c:\Program Files\Microsoft SQL Server\100\Tools\Binn\;c:\Program Files\Microsoft SQL Server\100\DTS\Binn\;C:\Program Files\QuickTime\QTSystem\;C:\Program Files\Common Files\DivX Shared\;C:\Program Files\WiTopia.Net\bin _SERVER["SystemRoot"] C:\WINDOWS _SERVER["COMSPEC"] C:\WINDOWS\system32\cmd.exe _SERVER["PATHEXT"] .COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH _SERVER["WINDIR"] C:\WINDOWS _SERVER["SERVER_SIGNATURE"] <address>Apache/2.2.14 (Win32) DAV/2 mod_ssl/2.2.14 OpenSSL/0.9.8l mod_autoindex_color PHP/5.3.1 mod_apreq2-20090110/2.7.1 mod_perl/2.0.4 Perl/v5.10.1 Server at localhost Port 80</address> _SERVER["SERVER_SOFTWARE"] Apache/2.2.14 (Win32) DAV/2 mod_ssl/2.2.14 OpenSSL/0.9.8l mod_autoindex_color PHP/5.3.1 mod_apreq2-20090110/2.7.1 mod_perl/2.0.4 Perl/v5.10.1 _SERVER["SERVER_NAME"] localhost _SERVER["SERVER_ADDR"] 127.0.0.1 _SERVER["SERVER_PORT"] 80 _SERVER["REMOTE_ADDR"] 127.0.0.1 _SERVER["DOCUMENT_ROOT"] C:/xampp/htdocs _SERVER["SERVER_ADMIN"] postmaster@localhost _SERVER["SCRIPT_FILENAME"] C:/xampp/htdocs/test.php _SERVER["REMOTE_PORT"] 3275 _SERVER["GATEWAY_INTERFACE"] CGI/1.1 _SERVER["SERVER_PROTOCOL"] HTTP/1.1 _SERVER["REQUEST_METHOD"] GET _SERVER["QUERY_STRING"] no value _SERVER["REQUEST_URI"] /test.php _SERVER["SCRIPT_NAME"] /test.php _SERVER["PHP_SELF"] /test.php _SERVER["REQUEST_TIME"] 1270600868 _SERVER["argv"] Array ( ) _SERVER["argc"] 0 PHP License This program is free software; you can redistribute it and/or modify it under the terms of the PHP License as published by the PHP Group and included in the distribution in the file: LICENSE This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. If you did not receive a copy of the PHP license, or have any questions about PHP licensing, please contact [email protected].

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• The Interaction between Three-Tier Client/Server Model and Three-Tier Application Architecture Model

  The three-tier client/server model is a network architectural approach currently used in modern networking. This approach divides a network in to three distinct components. Three-Tier Client/Server Model Components Client Component Server Component Database Component The Client Component of the network typically represents any device on the network. A basic example of this would be computer or another network/web enabled devices that are connected to a network. Network clients request resources on the network, and are usually equipped with a user interface for the presentation of the data returned from the Server Component. This process is done through the use of various software clients, and example of this can be seen through the use of a web browser client. The web browser request information from the Server Component located on the network and then renders the results for the user to process. The Server Components of the network return data based on specific client request back to the requesting client.  Server Components also inherit the attributes of a Client Component in that they are a device on the network and that they can also request information from other Server Components. However what differentiates a Client Component from a Server Component is that a Server Component response to requests from devices on the network. An example of a Server Component can be seen in a web server. A web server listens for new requests and then interprets the request, processes the web pages, and then returns the processed data back to the web browser client so that it may render the data for the user to interpret. The Database Component of the network returns unprocessed data from databases or other resources. This component also inherits attributes from the Server Component in that it is a device on a network, it can request information from other server components and database components, and it also listens for new requests so that it can return data when needed. The three-tier client/server model is very similar to the three-tier application architecture model, and in fact the layers can be mapped to one another. Three-Tier Application Architecture Model Presentation Layer/Logic Business Layer/Logic Data Layer/Logic The Presentation Layer including its underlying logic is very similar to the Client Component of the three-tiered model. The Presentation Layer focuses on interpreting the data returned by the Business Layer as well as presents the data back to the user.  Both the Presentation Layer and the Client Component focus primarily on the user and their experience. This allows for segments of the Business Layer to be distributable and interchangeable because the Presentation Layer is not directly integrated in with Business Layer. The Presentation Layer does not care where the data comes from as long as it is in the proper format. This allows for the Presentation Layer and Business Layer to be stored on one or more different servers so that it can provide a higher availability to clients requesting data. A good example of this is a web site that uses load balancing. When a web site decides to take on the task of load balancing they must obtain a network device that sits in front of a one or machines in order to distribute the request across multiple servers. When a user comes in through the load balanced device they are redirected to a specific server based on a few factors. Common Load Balancing Factors Current Server Availability Current Server Response Time Current Server Priority The Business Layer and corresponding logic are business rules applied to data prior to it being sent to the Presentation Layer. These rules are used to manipulate the data coming from the Data Access Layer, in addition to validating any data prior to being stored in the Data Access Layer. A good example of this would be when a user is trying to create multiple accounts under one email address. The Business Layer logic can prevent duplicate accounts by enforcing a unique email for every new account before the data is even stored in the Data Access Layer. The Server Component can be directly tied to this layer in that the server typically stores and process the Business Layer before it is returned to the end-user via the Presentation Layer. In addition the Server Component can also run automated process through the Business Layer on the data in the Data Access Layer so that additional business analysis can be derived from the data that has been already collected. The Data Layer and its logic are responsible for storing information so that it can be easily retrieved. Typical in most modern applications data is stored in a database management system however data can also be in the form of files stored on a file server. In addition a database can take on one of several forms. Common Database Formats XML File Pipe Delimited File Tab Delimited File Comma Delimited File (CSV) Plain Text File Microsoft Access Microsoft SQL Server MySql Oracle Sybase The Database component of the Networking model can be directly tied to the Data Layer because this is where the Data Layer obtains the data to return back the Business Layer. The Database Component basically allows for a place on the network to store data for future use. This enables applications to save data when they can and then quickly recall the saved data as needed so that the application does not have to worry about storing the data in memory. This prevents overhead that could be created when an application must retain all data in memory. As you can see the Three-Tier Client/Server Networking Model and the Three-Tiered Application Architecture Model rely very heavily on one another to function especially if different aspects of an application are distributed across an entire network. The use of various servers and database servers are wonderful when an application has a need to distribute work across the network. Network Components and Application Layers Interaction Database components will store all data needed for the Data Access Layer to manipulate and return to the Business Layer Server Component executes the Business Layer that manipulates data so that it can be returned to the Presentation Layer Client Component hosts the Presentation Layer that  interprets the data and present it to the user

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• SQL SERVER – Beginning of SQL Server Architecture – Terminology – Guest Post

  - by pinaldave

  SQL Server Architecture is a very deep subject. Covering it in a single post is an almost impossible task. However, this subject is very popular topic among beginners and advanced users.  I have requested my friend Anil Kumar who is expert in SQL Domain to help me write  a simple post about Beginning SQL Server Architecture. As stated earlier this subject is very deep subject and in this first article series he has covered basic terminologies. In future article he will explore the subject further down. Anil Kumar Yadav is Trainer, SQL Domain, Koenig Solutions. Koenig is a premier IT training firm that provides several IT certifications, such as Oracle 11g, Server+, RHCA, SQL Server Training, Prince2 Foundation etc. In this Article we will discuss about MS SQL Server architecture. The major components of SQL Server are: Relational Engine Storage Engine SQL OS Now we will discuss and understand each one of them. 1) Relational Engine: Also called as the query processor, Relational Engine includes the components of SQL Server that determine what your query exactly needs to do and the best way to do it. It manages the execution of queries as it requests data from the storage engine and processes the results returned. Different Tasks of Relational Engine: Query Processing Memory Management Thread and Task Management Buffer Management Distributed Query Processing 2) Storage Engine: Storage Engine is responsible for storage and retrieval of the data on to the storage system (Disk, SAN etc.). to understand more, let’s focus on the following diagram. When we talk about any database in SQL server, there are 2 types of files that are created at the disk level – Data file and Log file. Data file physically stores the data in data pages. Log files that are also known as write ahead logs, are used for storing transactions performed on the database. Let’s understand data file and log file in more details: Data File: Data File stores data in the form of Data Page (8KB) and these data pages are logically organized in extents. Extents: Extents are logical units in the database. They are a combination of 8 data pages i.e. 64 KB forms an extent. Extents can be of two types, Mixed and Uniform. Mixed extents hold different types of pages like index, System, Object data etc. On the other hand, Uniform extents are dedicated to only one type. Pages: As we should know what type of data pages can be stored in SQL Server, below mentioned are some of them: Data Page: It holds the data entered by the user but not the data which is of type text, ntext, nvarchar(max), varchar(max), varbinary(max), image and xml data. Index: It stores the index entries. Text/Image: It stores LOB ( Large Object data) like text, ntext, varchar(max), nvarchar(max),  varbinary(max), image and xml data. GAM & SGAM (Global Allocation Map & Shared Global Allocation Map): They are used for saving information related to the allocation of extents. PFS (Page Free Space): Information related to page allocation and unused space available on pages. IAM (Index Allocation Map): Information pertaining to extents that are used by a table or index per allocation unit. BCM (Bulk Changed Map): Keeps information about the extents changed in a Bulk Operation. DCM (Differential Change Map): This is the information of extents that have modified since the last BACKUP DATABASE statement as per allocation unit. Log File: It also known as write ahead log. It stores modification to the database (DML and DDL). Sufficient information is logged to be able to: Roll back transactions if requested Recover the database in case of failure Write Ahead Logging is used to create log entries Transaction logs are written in chronological order in a circular way Truncation policy for logs is based on the recovery model SQL OS: This lies between the host machine (Windows OS) and SQL Server. All the activities performed on database engine are taken care of by SQL OS. It is a highly configurable operating system with powerful API (application programming interface), enabling automatic locality and advanced parallelism. SQL OS provides various operating system services, such as memory management deals with buffer pool, log buffer and deadlock detection using the blocking and locking structure. Other services include exception handling, hosting for external components like Common Language Runtime, CLR etc. I guess this brief article gives you an idea about the various terminologies used related to SQL Server Architecture. In future articles we will explore them further. Guest Author  The author of the article is Anil Kumar Yadav is Trainer, SQL Domain, Koenig Solutions. Koenig is a premier IT training firm that provides several IT certifications, such as Oracle 11g, Server+, RHCA, SQL Server Training, Prince2 Foundation etc. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Security, SQL Server, SQL Tips and Tricks, SQL Training, T SQL, Technology

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• Big Data – Buzz Words: Importance of Relational Database in Big Data World – Day 9 of 21

  - by Pinal Dave

  In yesterday’s blog post we learned what is HDFS. In this article we will take a quick look at the importance of the Relational Database in Big Data world. A Big Question? Here are a few questions I often received since the beginning of the Big Data Series - Does the relational database have no space in the story of the Big Data? Does relational database is no longer relevant as Big Data is evolving? Is relational database not capable to handle Big Data? Is it true that one no longer has to learn about relational data if Big Data is the final destination? Well, every single time when I hear that one person wants to learn about Big Data and is no longer interested in learning about relational database, I find it as a bit far stretched. I am not here to give ambiguous answers of It Depends. I am personally very clear that one who is aspiring to become Big Data Scientist or Big Data Expert they should learn about relational database. NoSQL Movement The reason for the NoSQL Movement in recent time was because of the two important advantages of the NoSQL databases. Performance Flexible Schema In personal experience I have found that when I use NoSQL I have found both of the above listed advantages when I use NoSQL database. There are instances when I found relational database too much restrictive when my data is unstructured as well as they have in the datatype which my Relational Database does not support. It is the same case when I have found that NoSQL solution performing much better than relational databases. I must say that I am a big fan of NoSQL solutions in the recent times but I have also seen occasions and situations where relational database is still perfect fit even though the database is growing increasingly as well have all the symptoms of the big data. Situations in Relational Database Outperforms Adhoc reporting is the one of the most common scenarios where NoSQL is does not have optimal solution. For example reporting queries often needs to aggregate based on the columns which are not indexed as well are built while the report is running, in this kind of scenario NoSQL databases (document database stores, distributed key value stores) database often does not perform well. In the case of the ad-hoc reporting I have often found it is much easier to work with relational databases. SQL is the most popular computer language of all the time. I have been using it for almost over 10 years and I feel that I will be using it for a long time in future. There are plenty of the tools, connectors and awareness of the SQL language in the industry. Pretty much every programming language has a written drivers for the SQL language and most of the developers have learned this language during their school/college time. In many cases, writing query based on SQL is much easier than writing queries in NoSQL supported languages. I believe this is the current situation but in the future this situation can reverse when No SQL query languages are equally popular. ACID (Atomicity Consistency Isolation Durability) – Not all the NoSQL solutions offers ACID compliant language. There are always situations (for example banking transactions, eCommerce shopping carts etc.) where if there is no ACID the operations can be invalid as well database integrity can be at risk. Even though the data volume indeed qualify as a Big Data there are always operations in the application which absolutely needs ACID compliance matured language. The Mixed Bag I have often heard argument that all the big social media sites now a days have moved away from Relational Database. Actually this is not entirely true. While researching about Big Data and Relational Database, I have found that many of the popular social media sites uses Big Data solutions along with Relational Database. Many are using relational databases to deliver the results to end user on the run time and many still uses a relational database as their major backbone. Here are a few examples: Facebook uses MySQL to display the timeline. (Reference Link) Twitter uses MySQL. (Reference Link) Tumblr uses Sharded MySQL (Reference Link) Wikipedia uses MySQL for data storage. (Reference Link) There are many for prominent organizations which are running large scale applications uses relational database along with various Big Data frameworks to satisfy their various business needs. Summary I believe that RDBMS is like a vanilla ice cream. Everybody loves it and everybody has it. NoSQL and other solutions are like chocolate ice cream or custom ice cream – there is a huge base which loves them and wants them but not every ice cream maker can make it just right  for everyone’s taste. No matter how fancy an ice cream store is there is always plain vanilla ice cream available there. Just like the same, there are always cases and situations in the Big Data’s story where traditional relational database is the part of the whole story. In the real world scenarios there will be always the case when there will be need of the relational database concepts and its ideology. It is extremely important to accept relational database as one of the key components of the Big Data instead of treating it as a substandard technology. Ray of Hope – NewSQL In this module we discussed that there are places where we need ACID compliance from our Big Data application and NoSQL will not support that out of box. There is a new termed coined for the application/tool which supports most of the properties of the traditional RDBMS and supports Big Data infrastructure – NewSQL. Tomorrow In tomorrow’s blog post we will discuss about NewSQL. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Big Data, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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• Getting a Web Resource Url in non WebForms Applications

  - by Rick Strahl

  WebResources in ASP.NET are pretty useful feature. WebResources are resources that are embedded into a .NET assembly and can be loaded from the assembly via a special resource URL. WebForms includes a method on the ClientScriptManager (Page.ClientScript) and the ScriptManager object to retrieve URLs to these resources. For example you can do: ClientScript.GetWebResourceUrl(typeof(ControlResources), ControlResources.JQUERY_SCRIPT_RESOURCE); GetWebResourceUrl requires a type (which is used for the assembly lookup in which to find the resource) and the resource id to lookup. GetWebResourceUrl() then returns a nasty old long URL like this: WebResource.axd?d=-b6oWzgbpGb8uTaHDrCMv59VSmGhilZP5_T_B8anpGx7X-PmW_1eu1KoHDvox-XHqA1EEb-Tl2YAP3bBeebGN65tv-7-yAimtG4ZnoWH633pExpJor8Qp1aKbk-KQWSoNfRC7rQJHXVP4tC0reYzVw2&t=634533278261362212 While lately excessive resource usage has been frowned upon especially by MVC developers who tend to opt for content distributed as files, I still think that Web Resources have their place even in non-WebForms applications. Also if you have existing assemblies that include resources like scripts and common image links it sure would be nice to access them from non-WebForms pages like MVC views or even in plain old Razor Web Pages. Where's my Page object Dude? Unfortunately natively ASP.NET doesn't have a mechanism for retrieving WebResource Urls outside of the WebForms engine. It's a feature that's specifically baked into WebForms and that relies specifically on the Page HttpHandler implementation. Both Page.ClientScript (obviously) and ScriptManager rely on a hosting Page object in order to work and the various methods off these objects require control instances passed. The reason for this is that the script managers can inject scripts and links into Page content (think RegisterXXXX methods) and for that a Page instance is required. However, for many other methods - like GetWebResourceUrl() - that simply return resources or resource links the Page reference is really irrelevant. While there's a separate ClientScriptManager class, it's marked as sealed and doesn't have any public constructors so you can't create your own instance (without Reflection). Even if it did the internal constructor it does have requires a Page reference. No good… So, can we get access to a WebResourceUrl generically without running in a WebForms Page instance? We just have to create a Page instance ourselves and use it internally. There's nothing intrinsic about the use of the Page class in ClientScript, at least for retrieving resources and resource Urls so it's easy to create an instance of a Page for example in a static method. For our needs of retrieving ResourceUrls or even actually retrieving script resources we can use a canned, non-configured Page instance we create on our own. The following works just fine: public static string GetWebResourceUrl(Type type, string resource ) { Page page = new Page(); return page.ClientScript.GetWebResourceUrl(type, resource); } A slight optimization for this might be to cache the created Page instance. Page tends to be a pretty heavy object to create each time a URL is required so you might want to cache the instance: public class WebUtils { private static Page CachedPage { get { if (_CachedPage == null) _CachedPage = new Page(); return _CachedPage; } } private static Page _CachedPage; public static string GetWebResourceUrl(Type type, string resource) { return CachedPage.ClientScript.GetWebResourceUrl(type, resource); } } You can now use GetWebResourceUrl in a Razor page like this: <!DOCTYPE html> <html <head> <script src="@WebUtils.GetWebResourceUrl(typeof(ControlResources),ControlResources.JQUERY_SCRIPT_RESOURCE)"> </script> </head> <body> <div class="errordisplay"> <img src="@WebUtils.GetWebResourceUrl(typeof(ControlResources),ControlResources.WARNING_ICON_RESOURCE)" /> This is only a Test! </div> </body> </html> And voila - there you have WebResources served from a non-Page based application. WebResources may be a on the way out, but legacy apps have them embedded and for some situations, like fallback scripts and some common image resources I still like to use them. Being able to use them from non-WebForms applications should have been built into the core ASP.NETplatform IMHO, but seeing that it's not this workaround is easy enough to implement.© Rick Strahl, West Wind Technologies, 2005-2011Posted in ASP.NET  MVC   Tweet (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• SQLAuthority News – Why VoIP Service Providers Should Think About NuoDB’s Geo Distribution

  - by Pinal Dave

  You can always tell when someone’s showing off their cool, cutting edge comms technology. They tend to raise their voice a lot. Back in the day they’d announce their gadget leadership to the rest of the herd by shouting into their cellphone. Usually the message was no more urgent than “Hi, I’m on my cellphone!” Now the same types will loudly name-drop a different technology to the rest of the airport lounge. “I’m leveraging the wifi,” a fellow passenger bellowed, the other day, as we filtered through the departure gate. Nobody needed to know that, but the subtext was “look at me everybody”. You can tell the really advanced mobile user – they tend to whisper. Their handset has a microphone (how cool is that!) and they know how to use it. Sometimes these shouty public broadcasters aren’t even connected anyway because the database for their Voice over IP (VoIP) platform can’t cope. This will happen if they are using a traditional SQL model to try and cope with a phone network which has far flung offices and hundreds of mobile employees. That, like shouting into your phone, is just wrong on so many levels. What VoIP needs now is a single, logical database across multiple servers in different geographies. It needs to be updated in real-time and automatically scaled out during times of peak demand. A VoIP system should scale up to handle increased traffic, but just as importantly is must then go back down in the off peak hours. Try this with a MySQL database. It can’t scale easily enough, so it will keep your developers busy. They’ll have spent many hours trying to knit the different databases together. Traditional relational databases can possibly achieve this, at a price. Mind you, you could extend baked bean cans and string to every point on the network and that would be no less elegant. That’s not really following engineering principles though is it? Having said that, most telcos and VoIP systems use a separate, independent solution for each office location, which they link together – loosely.  The more office locations, the more complex and expensive the solution becomes and so the more you spend on maintenance. Ideally, you’d have a fluid system that can automatically shift its shape as the need arises. That’s the point of software isn’t it – it adapts. Otherwise, we might as well return to the old days. A MySQL system isn’t exactly baked bean cans attached by string, but it’s closer in spirit to the old many teethed mechanical beast that was employed in the first type of automated switchboard. NuoBD’s NewSQL is designed to be a single database that works across multiple servers, which can scale easily, and scale on demand. That’s one system that gives high connectivity but no latency, complexity or maintenance issues. MySQL works in some circumstances, but a period of growth isn’t one of them. So as a company moves forward, the MySQL database can’t keep pace. Data storage and data replication errors creep in. Soon the diaspora of offices becomes a problem. Your telephone system isn’t just distributed, it is literally all over the place. Though voice calls are often a software function, some of the old habits of telephony remain. When you call an engineer out, some of them will listen to what you’re asking for and announce that it cannot be done. This is what happens if you ask, say, database engineers familiar with Oracle or Microsoft to fulfill your wish for a low maintenance system built on a single, fluid, scalable database. No can do, they’d say. In fact, I heard one shouting something similar into his VoIP handset at the airport. “I can’t get on the network, Mac. I’m on MySQL.” You can download NuoDB from here. “NuoDB provides the ability to replicate data globally in real-time, which is not available with any other product offering,” states Weeks.  “That alone is remarkable and it works. I’ve seen it. I’ve used it.  I’ve tested it. The ability to deploy NuoDB removes a tremendous burden from our support and engineering teams.” Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL Tagged: NuoDB

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• SQL – Quick Start with Explorer Sections of NuoDB – Query NuoDB Database

  - by Pinal Dave

  This is the third post in the series of the blog posts I am writing about NuoDB. NuoDB is very innovative and easy-to-use product. I can clearly see how one can scale-out NuoDB with so much ease and confidence. In my very first blog post we discussed how we can install NuoDB (link), and in my second post I discussed how we can manage the NuoDB database transaction engines and storage managers with a few clicks (link). Note: You can Download NuoDB from here. In this post, we will learn how we can use the Explorer feature of NuoDB to do various SQL operations. NuoDB has a browser-based Explorer, which is very powerful and has many of the features any IDE would normally have. Let us see how it works in the following step-by-step tutorial. Let us go to the NuoDBNuoDB Console by typing the following URL in your browser: http://localhost:8080/ It will bring you to the QuickStart screen. Make sure that you have created the sample database. If you have not created sample database, click on Create Database and create it successfully. Now go to the NuoDB Explorer by clicking on the main tab, and it will ask you for your domain username and password. Enter the username as a domain and password as a bird. Alternatively you can also enter username as a quickstart and password as a quickstart. Once you enter the password you will be able to see the databases. In our example we have installed the Sample Database hence you will see the Test database in our Database Hierarchy screen. When you click on database it will ask for the database login. Note that Database Login is different from Domain login and you will have to enter your database login over here. In our case the database username is dba and password is goalie. Once you enter a valid username and password it will display your database. Further expand your database and you will notice various objects in your database. Once you explore various objects, select any database and click on Open. When you click on execute, it will display the SQL script to select the data from the table. The autogenerated script displays entire result set from the database. The NuoDB Explorer is very powerful and makes the life of developers very easy. If you click on List SQL Statements it will list all the available SQL statements right away in Query Editor. You can see the popup window in following image. Here is the cool thing for geeks. You can even click on Query Plan and it will display the text based query plan as well. In case of a SELECT, the query plan will be much simpler, however, when we write complex queries it will be very interesting. We can use the query plan tab for performance tuning of the database. Here is another feature, when we click on List Tables in NuoDB Explorer.  It lists all the available tables in the query editor. This is very helpful when we are writing a long complex query. Here is a relatively complex example I have built using Inner Join syntax. Right below I have displayed the Query Plan. The query plan displays all the little details related to the query. Well, we just wrote multi-table query and executed it against the NuoDB database. You can use the NuoDB Admin section and do various analyses of the query and its performance. NuoDB is a distributed database built on a patented emergent architecture with full support for SQL and ACID guarantees.  It allows you to add Transaction Engine processes to a running system to improve the performance of your system.  You can also add a second Storage Engine to your running system for redundancy purposes.  Conversely, you can shut down processes when you don’t need the extra database resources. NuoDB also provides developers and administrators with a single intuitive interface for centrally monitoring deployments. If you have read my blog posts and have not tried out NuoDB, I strongly suggest that you download it today and catch up with the learnings with me. Trust me though the product is very powerful, it is extremely easy to learn and use. Reference: Pinal Dave (http://blog.sqlauthority.com)   Filed under: Big Data, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: NuoDB

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• NoSQL Memcached API for MySQL: Latest Updates

  - by Mat Keep

  With data volumes exploding, it is vital to be able to ingest and query data at high speed. For this reason, MySQL has implemented NoSQL interfaces directly to the InnoDB and MySQL Cluster (NDB) storage engines, which bypass the SQL layer completely. Without SQL parsing and optimization, Key-Value data can be written directly to MySQL tables up to 9x faster, while maintaining ACID guarantees. In addition, users can continue to run complex queries with SQL across the same data set, providing real-time analytics to the business or anonymizing sensitive data before loading to big data platforms such as Hadoop, while still maintaining all of the advantages of their existing relational database infrastructure. This and more is discussed in the latest Guide to MySQL and NoSQL where you can learn more about using the APIs to scale new generations of web, cloud, mobile and social applications on the world's most widely deployed open source database The native Memcached API is part of the MySQL 5.6 Release Candidate, and is already available in the GA release of MySQL Cluster. By using the ubiquitous Memcached API for writing and reading data, developers can preserve their investments in Memcached infrastructure by re-using existing Memcached clients, while also eliminating the need for application changes. Speed, when combined with flexibility, is essential in the world of growing data volumes and variability. Complementing NoSQL access, support for on-line DDL (Data Definition Language) operations in MySQL 5.6 and MySQL Cluster enables DevOps teams to dynamically update their database schema to accommodate rapidly changing requirements, such as the need to capture additional data generated by their applications. These changes can be made without database downtime. Using the Memcached interface, developers do not need to define a schema at all when using MySQL Cluster. Lets look a little more closely at the Memcached implementations for both InnoDB and MySQL Cluster. Memcached Implementation for InnoDB The Memcached API for InnoDB is previewed as part of the MySQL 5.6 Release Candidate. As illustrated in the following figure, Memcached for InnoDB is implemented via a Memcached daemon plug-in to the mysqld process, with the Memcached protocol mapped to the native InnoDB API. Figure 1: Memcached API Implementation for InnoDB With the Memcached daemon running in the same process space, users get very low latency access to their data while also leveraging the scalability enhancements delivered with InnoDB and a simple deployment and management model. Multiple web / application servers can remotely access the Memcached / InnoDB server to get direct access to a shared data set. With simultaneous SQL access, users can maintain all the advanced functionality offered by InnoDB including support for Foreign Keys, XA transactions and complex JOIN operations. Benchmarks demonstrate that the NoSQL Memcached API for InnoDB delivers up to 9x higher performance than the SQL interface when inserting new key/value pairs, with a single low-end commodity server supporting nearly 70,000 Transactions per Second. Figure 2: Over 9x Faster INSERT Operations The delivered performance demonstrates MySQL with the native Memcached NoSQL interface is well suited for high-speed inserts with the added assurance of transactional guarantees. You can check out the latest Memcached / InnoDB developments and benchmarks here You can learn how to configure the Memcached API for InnoDB here Memcached Implementation for MySQL Cluster Memcached API support for MySQL Cluster was introduced with General Availability (GA) of the 7.2 release, and joins an extensive range of NoSQL interfaces that are already available for MySQL Cluster Like Memcached, MySQL Cluster provides a distributed hash table with in-memory performance. MySQL Cluster extends Memcached functionality by adding support for write-intensive workloads, a full relational model with ACID compliance (including persistence), rich query support, auto-sharding and 99.999% availability, with extensive management and monitoring capabilities. All writes are committed directly to MySQL Cluster, eliminating cache invalidation and the overhead of data consistency checking to ensure complete synchronization between the database and cache. Figure 3: Memcached API Implementation with MySQL Cluster Implementation is simple: 1. The application sends reads and writes to the Memcached process (using the standard Memcached API). 2. This invokes the Memcached Driver for NDB (which is part of the same process) 3. The NDB API is called, providing for very quick access to the data held in MySQL Cluster’s data nodes. The solution has been designed to be very flexible, allowing the application architect to find a configuration that best fits their needs. It is possible to co-locate the Memcached API in either the data nodes or application nodes, or alternatively within a dedicated Memcached layer. The benefit of this flexible approach to deployment is that users can configure behavior on a per-key-prefix basis (through tables in MySQL Cluster) and the application doesn’t have to care – it just uses the Memcached API and relies on the software to store data in the right place(s) and to keep everything synchronized. Using Memcached for Schema-less Data By default, every Key / Value is written to the same table with each Key / Value pair stored in a single row – thus allowing schema-less data storage. Alternatively, the developer can define a key-prefix so that each value is linked to a pre-defined column in a specific table. Of course if the application needs to access the same data through SQL then developers can map key prefixes to existing table columns, enabling Memcached access to schema-structured data already stored in MySQL Cluster. Conclusion Download the Guide to MySQL and NoSQL to learn more about NoSQL APIs and how you can use them to scale new generations of web, cloud, mobile and social applications on the world's most widely deployed open source database See how to build a social app with MySQL Cluster and the Memcached API from our on-demand webinar or take a look at the docs Don't hesitate to use the comments section below for any questions you may have 

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• Going to the Score Cards - Exceptional DBA Awards 2011

  - by Rodney

  This year marks my 4th year as a judge for the Exceptional DBA Awards, founded by Red Gate in 2008 to "recognize the essential but often overlooked contributions of DBAs, the unsung heroes of the IT community." As a professional DBA myself I have been honored to participate as a judge. It is not an easy job because there is a voluminous amount of nominees from all over the world. Each judge has to read through every word of the nominee's answers, deciding what makes each person special and stand out amongst their peers. What drives them? What single element of their submission will shine above all others? It is my hope that what I am about to divulge to you as a judge will prompt you to think about yourself or someone you know and decide that you may be the exceptional DBA who can take home the gold at this year's award ceremony in Seattle. We are more than a few weeks into the nomination process and there are quite a number of submissions already. I can not tell you how many as that would not be fair. I can say it is not 1 million or more. I can also say that it is not 100,000. But that is all I can say about that. However, I can tell you that it is enough this year that we are breaking records on the number of people who have been influenced, inspired or intrigued by the awards in the past. I remember them all like it were yesterday. fuzzy thought cloud here. It was a rainy day in Seattle (all memories for each award ceremony will start thusly) and I was in the hotel going over my notes on what I wanted to say about the winner of the 2008 Red Gate Exceptional DBA Award. The notes were on index cards that I had either bought or stolen from my wife, I do not recall, but I was nervous which was unlike me. This was, after all, a big night for the winner. Of course, we, the judges and the SQL community, had already decided the winner and now all that remained was to present the award. The room was packed. It was Casino night, sponsored by sqlservercentral.com. Money (fake), drinks (not fake) and camaraderie flowed through the room. Dan McClain won the award that year. He worked for Anheuser-Busch at the time. I promise that did not influence my decision. We presented Dan with the award. He was very proud of this achievement, rightfully so, as was the SQL community for him. I spoke with Dan throughout the conference and realized how huge this award was for him, not just personally but professionally. It was a rainy day in Seattle in 2009 and I was nervous. I was asked to speak to a group of people again as a judge for the Exceptional DBA Awards. This year, Josef Richberg would be the recipient of the award, but he would not be able to attend. We all prayed for him as he fought through an illness and congratulated him for his accomplishments as a DBA for his company. He got better and sallied forth and continued to give back to the SQL community that he saw as one big family. In 2010, and I am getting ahead of myself, he was asked to be a judge himself for the very award he had just received the year before. It was a sunny day in Seattle and I missed it, because it was in July and I was not there. It was a rainy day in Seattle and it is 2010 and Tracy Hamlin enters a submission that blows this judge away. She is managing a 50 Terabyte distributed database ("50 Gigabytes! Are you kidding me!!!", Rodney jokes.)  and loves her daily job as a DBA working with developers, mentoring them and teaching them best practices with kindness and patience. She is a people person who just happens to have 10+ years experience with RDBMS'. She wins the award and goes on to be recognized as famous at PASS. It will be a rainy day in Seattle this year when I sit amongst my old constituent judges and friends, Brad McGehee, http://www.simple-talk.com/books/sql-books/how-to-become-an-exceptional-dba,-2nd-edition/, Steve Jones, whom we all know and love at http://www.sqlservercentral.com and a young upstart to the SQL Community, this cat named Brent Ozar to announce the 2011 winner. I personally have not heard of Brent but I am told I have interviewed him for a DBA position several years ago and turned him down, http://www.brentozar.com/archive/2011/05/exceptional-dba-contest/ . I hope that did not jeopardize his future in the SQL world. I am a big hearted oaf and would feel horrible. Hopefully I will meet him at PASS and we can work this all out and I can help him get a DBA job. The rain has stopped and a new year is upon us. The stakes are high...the competition is fierce...the rewards are incredible. The entry form awaits you. http://www.exceptionaldba.com/ I very much look forward to meeting you and presenting the award to you in front of hundreds of your envious but proud peers as the new Exceptional DBA for 2011 at the PASS Summit. Here is what you could win: The Exceptional DBA of the Year receives full conference registration for the 2011 PSS Summit in Seattle, where the awards ceremony will take place, four nights' hotel accommodation, and $300 towards travel expenses. They will also be featured on Simple-Talk. Are you ready? Are you nervous?

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